Separable insulated connector system

ABSTRACT

Separable insulated connector systems for power distribution systems wherein the interfaces of the mating connectors are modified to reduce mating and separation force.

BACKGROUND OF THE INVENTION

The invention relates generally to cable connectors for electric powersystems, and more particularly to separable insulated connector systemsfor use with cable distribution systems.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a known electrical switchgear viewedfrom a source side of the switchgear.

FIG. 2 is another perspective view of the switchgear shown in FIG. 1viewed from a tap side of the switchgear.

FIG. 3 is a perspective view of internal components of the switchgearshown in FIGS. 1 and 2.

FIG. 4 is a longitudinal cross-sectional view of a known separableloadbreak connector system.

FIG. 5 is an enlarged cross-sectional view of a known female contactconnector that may be used in the loadbreak connector system shown inFIG. 4.

FIG. 6 is a cross sectional view of a separable deadbreak connectorformed in accordance with an exemplary embodiment of the invention.

FIG. 7 is a cross sectional view of an energized break female connectorformed in accordance with an exemplary embodiment of the invention.

FIG. 8 is a top view of an exemplary mating connector for the maleconnector shown in FIG. 7.

FIG. 9 is a vertical cross sectional view of the connector shown in FIG.8.

FIG. 10 schematically illustrates a first connector interface for theconnectors shown in FIGS. 7 and 9.

FIGS. 11 and 12 schematically illustrate an exemplary embodiment of analternative connector interface for the connectors shown in FIGS. 7 and9.

FIGS. 13 and 14 illustrate an exemplary embodiment of anotheralternative for a connector interface for the connectors shown in FIGS.7 and 9.

FIGS. 15 and 16 illustrate an exemplary embodiment of a thirdalternative for a connector interface for the connectors shown in FIGS.7 and 9.

FIGS. 17 and 18 illustrate an exemplary embodiment of yet anotheralternative for a connector interface for the connectors shown in FIGS.7 and 9.

FIG. 19 illustrates a side view of an alternative exemplary connectorinterface embodiment having a waffle pattern for use with the connectorsshown in FIGS. 7 and 9.

FIG. 20 illustrates a side view of an alternative exemplary connectorinterface embodiment having a geometric pattern for use with theconnectors shown in FIGS. 7 and 9.

FIG. 21 illustrates a side view of an alternative exemplary connectorinterface embodiment having dimples for use with the connectors shown inFIGS. 7 and 9.

FIG. 22 illustrates exemplary test data for the exemplary connectorinterface embodiment of FIGS. 11 and 12.

FIG. 23 illustrates an exemplary power system for use of the exemplaryconnectors in the switchgear of FIGS. 1 and 2.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Electrical power is typically transmitted from substations throughcables which interconnect other cables and electrical apparatus in apower distribution network. The cables are typically terminated onbushings that may pass through walls of metal encased equipment such ascapacitors, transformers or switchgear. Such cables and equipmenttransmit electrical power at medium and high voltages generally greaterthan 600V.

Separable connector systems have been developed that allow readyconnection and disconnection of the cables to and from the electricalequipment. In general, two basic types of separable connector systemshave conventionally been provided, namely deadbreak connector systemsand livebreak connector systems.

Deadbreak connector systems require connection or disconnection ofcables while the equipment and the cables are de-energized. That isdeadbreak connectors are mated and separated only when there is novoltage and no load current between the contacts of the connectors andthe bushings of the equipment. Deadbreak connector systems for highvoltage equipment are typically rated for currents of about 600 A.

To avoid power interruptions required by deadbreak connector systems,loadbreak connector systems have been developed that allow connectionand disconnection to equipment under its operating voltage and loadcurrent conditions. Loadbreak connector systems, however, are typicallyrated for much lower currents of about 200 A in comparison to deadbreakconnector systems.

Exemplary embodiments of the inventive separable insulated connectorsystems are described herein below. In one exemplary embodiment, theinventive separable insulated connector systems are operable inswitchgear and other electrical equipment at higher current ratings thanconventional deadbreak or livebreak connector systems. The connectorsmay be provided at relatively low cost, and facilitate installation andremoval of protection modules to the equipment without having to powerdown the equipment, but in a different manner from conventionallivebreak connector systems. The inventive connector systems aresometimes referred to as energized break connectors, which shall referto the making and breaking of electrical connections that are energizedat their rated voltage, but not carrying load current. Such conditionsmay occur, for example, when protective elements such as fuses and thelike operate to interrupt electrical current through a portion of theelectrical equipment. The separable energized break connector systemspermit the protection modules to be replaced while the equipment isenergized and still in service.

In order to fully appreciate the exemplary energized break connectorsystems described later below, some appreciation of electricalequipment, and different types of conventional connectors, namelylivebreak and deadbreak connector systems for such electrical equipment,is necessary.

A. The Electrical Equipment

FIG. 1 illustrates an exemplary electrical equipment configuration 100with which the connectors, described below, may be used. While in anexemplary embodiment the electrical equipment 100 is a particularconfiguration of switchgear, it is understood that the benefits of theexemplary embodiment accrue generally to switchgear of manyconfigurations, as well as electrical equipment of different types andconfigurations, including but not limited to a power distributioncapacitor or transformer. That is, the switchgear 100 is but onepotential application of the inventive connector assemblies and systemsdescribed hereinbelow. Accordingly, the switchgear 100 is illustratedand described herein for illustrative purposes only, and is not intendedto be limited to any particular type of switchgear configuration, suchas the switchgear 100, or to any particular type of electricalequipment.

As shown in FIG. 1, the switchgear 100 includes a protective enclosure102 having, for example, a source side door 104 positionable between anopen position (FIG. 1) and a closed position (FIG. 2). Latch elements106 and/or 108 may be used to lock source side door 104 in a closedposition. Inside the source side door 104 is a front plate 110 thatforms a portion of the enclosure 102. Cables 112 a-112 f may be coupledto a lower end of the enclosure 102 and are connected to activeswitching elements (described below) in the enclosure 102, and each ofthe cables 112 a-112 f typically carry power in three phases from twodifferent sources. For example, cables 112 a-112 c may carry,respectively, the A, B and C phases of power from source 1, and cables112 d-112 f may carry, respectively, the C, B and A phases of power fromsource 2.

Cables 112 a-112 f may be coupled to the front-plate 110 and switchgear100 through, for example, connector components 114 a-114 f that join thecables 112 a-112 f to respective switching elements (not shown inFIG. 1) in the enclosure 102. The switching elements may, in turn, becoupled to an internal bus bar system (not shown in FIG. 1) in theenclosure 102.

Handles or levers 116 a and 116 b are coupled to the enclosure 102 andmay operate active switchgear elements (described below) inside theswitchgear 100 to open or interrupt the flow of current through theswitchgear 100 via the cables 112 a-112 f and electrically isolate powersources 1 and 2 from load-side or power receiving devices. The cables112 a-112 c may be disconnected from the internal bus bar system bymanipulating the handle 116 a. Similarly, cables 112 d-112 f may bedisconnected from the internal bus bar system by manipulating the handle116 b. Handles 116 a and 116 b are mounted onto the front-plate 110 asshown in FIG. 1. In an exemplary embodiment, the active switch elementson the source side of the switchgear 100 are vacuum switch assemblies(described below), and the vacuum switch assemblies may be used incombination with other types of fault interrupters and fuses in variousembodiments of the invention.

One exemplary use of switchgear is to segregate a network of powerdistribution cables into sections such as, for example, by opening orclosing the switch elements. The switch elements may be opened orclosed, either locally or remotely, and the power supplied from onesource to the switchgear may be prevented from being conducted to theother side of the switchgear and/or to the bus. For example, by openingthe switch levers 116 a and 116 b, power from each of the sources 1 and2 on one side of the switchgear is prevented from being conducted to theother side of the switchgear and to the bus and the taps. In thismanner, a utility company is able to segregate a portion of the networkfor maintenance, either by choice, through the opening of switchgear, orautomatically for safety, through the use of a fuse or faultinterrupter, depending on the type of active switching elements includedin the switchgear.

FIG. 23 illustrates the use of the exemplary switchgear in an exemplarypower distribution system 2300. A power plant 2305 or other powerproducing means know to those of skill in the art transmits power overhigh voltage cables 2307 to a substation 2310. While the currentembodiment shows only one substation 2310, those of skill in the artwill recognize that a number of substations may be employed between thepower production facility 2305 and the customers receiving the power.

The contents of the substation have been simplified for means ofexplanation and can include a high voltage switchgear 2315 and a lowvoltage switchgear 2320 on each side of a transformer 2320. Power maythen be transmitted through low voltage electrical protection 2330before being transmitted to the customers. The low voltage electricalprotection 2330 may include fuses and or circuit breakers, as well asmeans for connecting the cables from the second switchgear 2325 to thelow voltage electrical protection 2330 and from the low voltageelectrical protection 2330 to the customers 2335. The switchgears 2315and 2325 are typically located on both the high voltage and low voltageside of the power transformer 2320 as shown in FIG. 23. The substationmay also include fuses (not shown) to protect the transformer 2320.

The transformer 2320 transfers energy from one electrical circuit toanother by magnetic coupling. The transformer 2320 typically includestwo or more coupled windings and a magnetic core to concentrate magneticflux. A voltage applied to one winding creates a time-varying magneticflux in the core, which induces a voltage in the other windings. Varyingthe relative number of turns determines the voltage ratio between thewindings, thus transforming the voltage from one circuit to another.

FIG. 2 illustrates another side of the switchgear 100 including a tapside door 120 that is positionable between open (shown in FIG. 2) andclosed (FIG. 1) positions in an exemplary embodiment. Latch elements 122and/or 124 may be used to lock the tap side door 120 in the closedposition. Inside the tap door 120 is a front-plate 126 that defines aportion of the enclosure 102. Six cables 128 a-128 f may be connected toa lower side of the switchgear 100, and each of the respective cables128 a-128 f typically carries, for example, one phase of power away fromswitchgear 100. For example, cable 128 a may carry A phase power, cable128 b may carry B phase power and cable 128 c may carry C phase power.Similarly, cable 128 d may carry C phase power, cable 128 e may carry Bphase power and cable 128 f may carry A phase power. Connectors 130a-130 f connect cables 128 a-128 f to switchgear.

It should be noted that the exemplary switchgear 100 in FIGS. 1 and 2shows one only one exemplary type of phase configuration, namely an ABCCBA configuration from left to right in FIG. 2 so that the correspondingcables 128 a-128 c and 128 d-128 f carry the respective phases ABC andCBA in the respective tap 1 and tap 2. It is understood, however, thatother phase configurations may be provided in other embodiments,including but not limited AA BB CC so that cables 128 a and 128 b eachcarry A phases of current, cables 128 c and 128 d each carry B phases ofcurrent, and so that cables 128 e and 128 f each carry C phases ofcurrent. Still other configurations of switchgear may have one or moresources and taps on the same front-plate 110 (FIG. 1) or 126 (FIG. 2),or on the sides of the switchgear on one or more additional frontplates. It also contemplated that each phase may be designated by anumber, such as 1, 2 and 3, and that the switchgear may accommodate moreor less than three phases of power. Thus, a switchgear may have, forexample only, a configuration of 123456 654321 on the tap side of theswitchgear 100.

A frame may be positioned internal to the switchgear and provide supportfor the active switching elements as well as the bus bar system,described below. In other words, the frame holds the active switchingelements and bus bar system in place once they are coupled to the frame.The frame is oriented to allow portions of the active switchingelements, typically bushings, to protrude as a bushing plane so thatconnections to the various cables can be made.

In an exemplary embodiment, a lever or handle 132 a operates activeswitchgear elements, as described below, inside the switchgear 100 todisconnect cables 128 a, 128 b, 128 c from the internal bus bar system.Similarly, handles 132 b-132 d cause one of individual cables 128 d, 128e, 128 f to disconnect and connect, respectively, from the internal busbar system. In an exemplary embodiment, the active switchgear elementson the tap side of the switchgear 100 include vacuum interrupterassemblies (described below), and the vacuum interrupter assemblies maybe used in combination with fuses and various types of faultinterrupters in further and/or alternative embodiments.

FIG. 3 is a perspective view of exemplary internal components of theswitchgear 100 removed from the enclosure 102 and without the supportingframe. Switch element assemblies 150 and protective element assemblies152 such as fuses, breakers, interrupter assemblies and the like may bepositioned on opposites sides (i.e., the source side and the tap side,respectively) of the switchgear assembly. Cables 112 a-112 f may beconnected to respective switch element assemblies 150, and cables 128a-128 f (cables 128 c-128 f not labeled in FIG. 3) may be connected tothe respective interrupter element assemblies 152.

A bus bar system 154 may be situated in between and may interconnect theswitch element or interrupter assemblies 150 and 152 via connectors 156and 158. In different embodiments, the bus bar system 154 includesconventional metal bar members formed or bent around one another, or amodular cable bus and connector system. The modular cable bus system maybe assembled with mechanical and push-on connections into variousconfigurations, orientations of phase planes, and sizes of bus barsystems. In still another embodiment, molded solid dielectric bus barmembers may be provided in modular form with push-on mechanicalconnectors to facilitate various configurations of bus bar systems witha reduced number of component parts. In still other embodiments, otherknown bus bar systems may be employed as those in the art willappreciate.

When certain types of protective elements 152 are utilized in theswitchgear, it may be necessary to replace the protective elements 152as they operate to interrupt the circuit path. In particular, when fusesare utilized in the elements 152 and the fuse elements open a currentpath through the respective protective element 152, it must be removedand replaced to restore the electrical connection. In such acircumstance, an opened fuse remains at its operating voltage potentialor rated voltage, but carries no load current because the current paththrough the fuse is opened. An opened fuse or fuses in the respectiveprotective elements 152 may impair the full power service of theswitchgear to some degree by interrupting or reducing power supply toloads and equipment directly connected to the opened fuse(s), whileprotective elements 152 that have not opened may continue to supplyelectrical power to other electrical loads and equipment.

B. Conventional Loadbreak Connector Systems

FIG. 4 is a longitudinal cross-sectional view of a conventionalseparable loadbreak connector system 200 that may be utilized to connectand disconnect cables to the switchgear 100 under energized circuitconditions at rated voltage and under electrical load currentconditions.

As shown in FIG. 4, the loadbreak connector system 200 includes a maleconnector 202 and a female connector 204. The female connector 204 maybe, for example, a bushing insert or connector connected to theswitchgear 100, for example, or another electrical apparatus such as acapacitor or transformer, and the male connector 202, may be, forexample, an elbow connector, electrically connected to a respective oneof the cables 112 (FIGS. 1 and 3). The male and female connectors 202,204 respectively engage and disengage one another to achieve electricalconnection or disconnection to and from the switchgear 100 or otherelectrical apparatus.

While the male connector 202 is illustrated as an elbow connector inFIG. 4, and while the female connector 204 is illustrated as a bushinginsert, the male and female connectors may be of other types andconfigurations known in the art.

In an exemplary embodiment, and as shown in FIG. 4, the male connector202 may include an elastomeric housing 210 of a material such as EPDM(ethylene-propylene-dienemonomer) rubber which is provided on its outersurface with a conductive shield layer 212 which is connected toelectrical ground. One end of a male contact element or probe 214, of amaterial such as copper, extends from a conductor contact 216 within thehousing 210 into a cup shaped recess 218 of the housing 210. An arcfollower 220 of ablative material, such as acetal co-polymer resinloaded with finely divided melamine in one example, extends from anopposite end of the male contact element 214. The ablative material maybe injection molded on an epoxy bonded glass fiber reinforcing pin 222.A recess 224 is provided at the junction between metal rod 214 and arcfollower 220. An aperture 226 is provided through the exposed end of rod214 for the purpose of assembly.

The female connector 204 may be a bushing insert composed of a shieldassembly 230 having an elongated body including an inner rigid,metallic, electrically conductive sleeve or contact tube 232 having anon-conductive nose piece 234 secured to one end of the contact tube232, and elastomeric insulating material 236 surrounding and bonded tothe outer surface of the contact tube 232 and a portion of the nosepiece 234. The female connector 204 may be electrically and mechanicallymounted to a bushing well (not shown) disposed on the enclosure of theswitchgear 100 or a transformer or other electrical equipment.

A contact assembly including a female contact 238 having deflectablecontact fingers 240 is positioned within the contact tube 232, and anarc interrupter 242 is provided proximate the female contact 238.

The male and female connectors 202, 204 are operable or matable during“loadmake”, “loadbreak”, and “fault closure” conditions. Loadmakeconditions occur when the one of the contact elements, such as the malecontact element 214 is energized and the other of the contact elements,such as the female contact element 238 is engaged with a normal load. Anarc of moderate intensity is struck between the contact elements 214,238 as they approach one another and until joinder under loadmakeconditions. Loadbreak conditions occur when the mated male and femalecontact elements 214, 238 are separated when energized and supplyingpower to a normal load. Moderate intensity arcing again occurs betweenthe contact elements 214, 238 from the point of separation thereof untilthey are somewhat removed from one another. Fault closure conditionsoccur when the male and female contact elements 214, 238 are mated withone of the contacts being energized and the other being engaged with aload having a fault, such as a short circuit condition. Substantialarcing occurs between the contact elements 214, 238 in fault closureconditions as the contact elements approach one another they are joined.In accordance with known connectors of this type, expanding gas isemployed to accelerate the female contact 238 in the direction of themale contact element 240 as the connectors 202, 204 are engaged, thusminimizing arcing time and hazardous conditions.

FIG. 5 illustrates another conventional female connector 250 that may beused in the connector system 200 (FIG. 4) in lieu of the femaleconnector 204. Like the connector 204, the female connector 250 includesan elongated body including an inner rigid, metallic, electricallyconductive sleeve or contact tube 252 having a non-conductive nose piece254 secured to one end of the contact tube 252, and elastomericinsulating material 256 surrounding and bonded to the outer surface ofthe contact tube 252 and a portion of the nose piece 254.

A contact assembly includes a piston 258 and a female contact element260 having deflectable contact fingers 262 is positioned within thecontact tube 252 and an arc interrupter 264 is provided proximate thefemale contact 260. The piston 258, the female contact element 260, andthe arc interrupter 264 are movable or displaceable along a longitudinalaxis of the connector 250 in the direction of arrow A toward the malecontact element 214 (FIG. 4) during a fault closure condition. Toprevent movement of the female contact 260 beyond a predetermined amountin the fault closure condition, a stop ring 266 is provided, typicallyfabricated from a hardened steel or other rigid material.

Loadbreak connector systems can be rather complicated in theirconstruction, and are typically provided with current ratings of about200 A or below due to practical limitations in making and breakingconnections carrying load current. Also, the load break, load make andfault closure features of such connectors are of no practical concernfor applications such as that described above wherein removal andreplacement of fuse modules involves making and breaking of connectionsunder energized circuit conditions at rated voltage, but not under loadcurrent conditions.

C. Conventional Deadbreak Connector Systems

FIG. 6 is a cross sectional schematic view of an exemplary conventionalfemale connector 300 of a deadbreak connector system. As shown in FIG.6. the female connector 300 may be a bushing insert composed of a shieldassembly 302 having an elongated body including an inner rigid,metallic, electrically conductive sleeve or contact tube 304 andelastomeric insulating material 306 surrounding and bonded to the outersurface of the contact tube 304. A conductive ground plane 307 may beprovided on an outer surface of the housing 306. The female connector300 may be electrically and mechanically mounted to the enclosure of theswitchgear 100 or other electrical equipment.

A contact assembly including a female contact 308 having deflectablecontact fingers 310 is positioned within the contact tube 304. Unlikethe loadbreak connector system previously described, the contact 308 isfixedly secured and is not movable relative to the contact tube 304.Also as shown in FIG. 6, conductive portions of the connector 300 aregenerally exposed at and end 312 of the connector. In particular, theend of the contact tube 304, which in use is at the operating voltagepotential of the female contact 308, is generally exposed at the end 312of the connector 304.

Because conductive components of the connector 300 are exposed at theconnector end 312, if subjected to large operating voltages in theabsence of load current conditions as described above when a fuseelement operates, voltage flashover may occur between the exposedconductive components and a male contact probe 314 of a mating connectoras the connectors are separated or mated. Voltage flashover may alsooccur from the exposed conductive components at the connector end 312 tothe connector ground plane 307. Such flashover may present a hazardouscondition and is undesirable.

Additionally, as previously mentioned, known deadbreak connectors aretypically constructed to provide current ratings of about 600 A or less.Connectors with higher ratings are desirable.

II. Separable Insulated Connector Systems

FIG. 7 is a cross sectional view of an energized break female connector400 formed in accordance with one exemplary embodiment that overcomesthe various problems and difficulties discussed above in Part I. Asused, herein, “energized break” shall refer to energized circuitconditions wherein rated voltage potential exists but load current doesnot exist due to, for example, a protective element such as a fuseopening a current path. It is recognized that the description andfigures set forth herein are set forth for illustrative purposes only,and that the benefits may accrue to other types of electrical equipment.The illustrated embodiments of switchgear and connectors are merelyexemplary configurations of devices and equipment embodying theinventive concepts herein.

Likewise, while the energized break connector 400 is described anddepicted herein having a particular configuration with certainattributes, materials, shape and dimension, it is understood thatvarious embodiments having other, materials, shape and dimension maylikewise be constructed within the scope and spirit of the invention.

As shown in FIG. 7, the female connector 400 may be a bushing inserthaving of a shield assembly 402 formed with an elongated body includingan inner rigid, metallic, electrically conductive sleeve or contact tube404 defining an axial passage 405, and elastomeric insulating material406 (also termed the “housing”) forming a housing surrounding and bondedto the outer surface of the contact tube 404. While the connector isillustrated with a particular shape of contact tube 404 and housing 406,other shapes of these components may also be utilized as desired.

A conductive ground plane 408 may be provided on an outer surface of thehousing 406 for safety reasons. The female connector 400 may beelectrically and mechanically mounted to a bushing well (not shown)disposed on the enclosure of the switchgear 100 or other electricalequipment. Alternatively, the female connector 400 may be utilized forother purposes.

A contact assembly including a female contact 410 having deflectablecontact fingers 412 is positioned within the contact tube 404. While aparticular type and shape of contact 410 is illustrated, it isrecognized that other types of contacts may be utilized.

Like the deadbreak connector system 300 (FIG. 6) previously described,the contact 410 is fixedly secured and is not movable relative to thecontact tube 404 in any operating condition, in specific contrast to theloadbreak connector 204 and 250 (FIGS. 4 and 5) having a movable contactassembly during fault closure conditions. Unlike either of the loadbreakand deadbreak connectors previously described, the energized breakconnector 400 includes a continuous, uninterrupted, bonded insulationsystem 414 extending from the contact fingers 412 to the ground plane408 on the outer surface of the housing 406.

The insulation system 414 includes a nonconductive nosepiece 416 and aportion of the housing 406 as described below. The nosepiece 416 extendssubstantially an entire distance along an axis 418 of the connector fromthe contact fingers 412 to a distal open end 420 of the connector thatreceives a male contact probe of a mating connector (not shown in FIG.7). The nosepiece 416 may be fabricated from a nonconductive materialsuch as nylon in an exemplary embodiment, although other materials maylikewise be used to form the nosepiece 416.

In one embodiment, the nosepiece 416 may mechanically engage the contacttube 404 with snap fit engagement. In another embodiment, threads andother fasteners, including adhesives and the like, may be utilized toattach to the nosepiece 414 to the contact tube 404 and/or anothercomponent of the connector 400. In still another embodiment, thenosepiece 416 may be molded into the connector construction if desired.

In one exemplary embodiment, the nosepiece 416 may be shaped orotherwise formed into a substantially cylindrical body that overlaps ansubstantially covers an interior surface of the contact tube 404 for anaxial distance along the axis 418 from a point proximate or adjacent tothe contact fingers 412 to a distal end 422 of the contact tube 404, andalso extends an axial distance from contact tube end 422 to the distalopen end 420 of the connector. The elastomeric housing 406 also extendswell beyond the distal end 422 of the contact tube 404 and overlies anexterior surface of a portion of the nosepiece 416 extending forwardlyof the distal end 422 of the contact tube.

An inner surface 424 of the nosepiece may be generally smooth andconstant in dimension, and defines a continuously insulated path fromthe end of the contact fingers 412 along the passage 405 of the contacttube 404 to the distal end 420 of the connector 400. An exterior surface426 of the nosepiece may be irregular in shape, and may include a firstportion of a relatively larger outer diameter that meets a portion ofthe housing 406 adjacent the distal end 420, and a portion of relativelysmaller outer diameter that is received within the contact tube 404 andprovides an insulative barrier on the inner surface of the contact tube404.

While an exemplary shape of the nosepiece 416 has been described havingportions of different diameters and the like, it is recognized that thenosepiece may be alternatively shaped and formed in other embodiments,while still achieving the same benefits.

The extension of the nosepiece 416 and the housing 406 beyond the distalend 422 of the contact tube 404 effectively spaces the female contact410, and particularly the contact fingers 412, farther from the distalend 420 of the connector 400. In other words, the extension of thenosepiece 416 and the housing 406 results in the female contact beingfurther recessed in the contact tube 404 relative to the end 420 of theconnector. This accordingly mitigates flashover between the contactfingers 412 and the distal end 420 of the connector 400 when the femaleconnector 400 is engaged to or separated from a male contact probe of amating connector, which may be the male connector of a fuse module inthe electrical equipment. The non-conductive nosepiece 416 and theextended housing 406 fully insulate the distal end 420 of the connector400 such that no conductive component is exposed proximate the distalend 420. Flashover at, for example, the distal end 420 of the contacttube 404 is accordingly avoided.

Extension of the housing 406 to meet the extended nosepiece 416 at adistance from the end 422 of the contact tube also effectively increasesa path length on the outer surface of the connector interface 428between the connector distal end 420 and the ground plane. The increasedpath length along the inner surface 424 of the nosepiece 416 and theincreased path length on the outer surface of the interface 428 of thehousing 406 is believed to substantially reduce, if not altogethereliminate, instances of flashover between the contact fingers 412 andthe ground plane 408. The longer interface creep distance also yieldsbetter static dielectric performance of the connector 400.

As is also clear from FIG. 7, the nosepiece 416 and/or the elastomerichousing 406 are devoid of any venting features and the like that arecommon to loadbreak connector systems for releasing arc quenching gasesand the like. That is, no air gaps or passages for gas are formed intothe energized break connector construction, and instead the insulativenosepiece 416 and the elastomeric housing 416 are uniformly constructedin a solid manner without discontinuities, openings, gaps or spacesformed therein and therebetween that may otherwise present voltagetracking and flashover concerns.

By virtue of the above-described construction, the connector 400 mayenjoy current ratings up to, for example, 900 A in an economical andeasy to manufacture platform. The energized break separable connector400 is matable to and separable from a mating connector with ratedvoltage between the connector contacts but without load current, and mayeffectively allow replacement of fuse element modules in electricalequipment while the equipment remains in service and with minimaldisruption to a power distribution system.

FIGS. 8 and 9 are a top view, and a cross sectional view of a maleconnector 450 that may be utilized with the energized break connector400 of FIG. 7. The male connector 450 includes an elastomeric housing452 and a ground plane 454 provided on the housing 452. The housing 452defines a connector interface 456, and a contact assembly including acontact probe 458 is situated within the housing 452 and extends along apassage defined by the interface 456. A conductive extension member 460may be coupled to an end of the contact probe 458 and may projectoutwardly and away from the interface 456 for a specified distance. Thelength of the extension member 460 accommodates the extended nosepiece416 and housing 406 (FIG. 7) of the connector 400 and ensures thatsufficient mechanical and electrical contact is made between the contact410 (FIG. 7) and the contact extension 460 of the male connector 450.

When the connector 450 is mated with the connector 400 (FIG. 7), theinterface 428 of the connector 400 is received within the interface 456of the connector 450, and the male contact probe 458 and contactextension 460 are extended through the open end 420 of the connector 400until the contact extension 460 is in mechanical and electricalengagement with the contact fingers 412.

The connector 450 may also include a semiconductive insert such as afaraday cage 462, which has the same electric potential as the contactprobe 458. The faraday cage 462 prevents corona discharges withininterface 456 when the connector 452 is mated, for example, to thefemale connector 400 (FIG. 7).

The male connector 450 may be configured as an elbow connector thatengages the female connector 400 via the interface 456 on one end, andengages, for example, a fuse element module on another end (not shown inFIGS. 9 and 10). Alternatively, the connector 450 may be configured intoa another type of connector having any shape or configuration desired.The connector 450 may also be configured as a protective cap for usewith the female connector 400 that is energized at rated voltage asdescribed above.

FIG. 10 schematically illustrates a first connector interface for theconnectors 400 and 450 shown in FIGS. 7 and 9, respectively,illustrating the connectors 400 being mated to one another.

The female connector interface 428 may be generally conical in shape inone embodiment, and may have a tapered outer surface 428 of a generallydecreasing diameter from left to right as depicted in FIG. 10. Thefemale connector interface 428 may be generally smooth and continuoussuch that the outer diameter along the interface 428 decreases at agenerally constant rate along the axis of the female connector 400.

The male connector interface 456 forms a recess, cavity or passage 468that receives the female connector interface 428, and as such may becomplementary in shape and profile. As such, in the exemplary embodimentof FIG. 10 the male connector interface 456 may also be generallyconical in shape or form, and accordingly has a tapered inner surface470 of a generally decreasing diameter from left to right as depicted inFIG. 10. The male connector interface 456 may be generally smooth andcontinuous such that the outer diameter along the interface 456decreases at a generally constant rate along the axis of the maleconnector 450. The conductive insert defining the faraday cage 462around a portion of the contact probe 458 abuts one end 472 of the maleconnector 456, and the interface 456 extends between the faraday cage462 and a mouth or rim 474 at the end of the connector 450.

When the axis of each connector 400 and 450 is aligned, the connectors400 and 450 are movable toward one another along an insertion axis 476to a fully engaged position wherein the female connector interface 428is fully received in the male connector interface 456. When so engaged,the contact probe 458 is extended through the passage 405 of theconnector 400 and into mechanical and electrical contact with the femalecontact element 410.

As the connectors are mated, the outer surface of the female connectorinterface 428 and the inner surface 470 of the female connectorinterface 450 are generally parallel to one another such that the femaleconnector interface 428 is self-aligning within the male connectorinterface 456. The continuous and generally parallel interfaces 428 and456 are sometimes referred to as a straight-line interface. The femaleconnector interface 428 is slidably received in the interface 456 of theconnector 462 with generally complete surface-to-surface engagementbetween the outer surface of the interface 428 and the inner surface 470of the interface 456. Because the mating interfaces 428 and 456 are eachformed with elastomeric insulation, and because the outer dimensions ofthe interface 428 are selected to provide a slight interference fitwithin the interface 456, some difficulty may result in sliding theconnectors 400 and 450 together to mate them or to separate them.

To reduce the amount of force needed to mate or separate the connectors400 and 450, in operation, silicon grease, silicon oil, or otherlubricants known in the art are applied between the female connectorinterface 428 and the interface 456 of the connector 462. However,because of the need for an interference fit the connector 450 isconstantly squeezing down upon the connector 400 in order to keep waterand other elements out and keep in electrons. Because the connectors areconical, the constant squeezing also can extrude the silicon grease offof the interfaces 428 and 456. Over time, the grease migrates down theinterface. Once some of the grease has migrated, it becomes moredifficult to separate the connectors 400 and 450.

It is believed that the conductive insert forming the faraday cage 462,that is subject to the same operating voltage potential as the contactprobe 458 in use, presents a somewhat increased likelihood of voltagetracking along the male connector interface 456, and presentsopportunity for potential flashover from the male connector interface456 to the ground plane 454 of the male connector 450.

FIGS. 11 and 12 schematically illustrates an alternative connectorinterface that may be utilized in the connectors 400 and 450 shown inFIGS. 7 and 9 that may be less susceptible to voltage tracking andpotential flashover. Like reference characters of the previous figuresare therefore used to indicate like features in FIG. 11.

Unlike the straight line male connector interface 456 previouslydescribed above in relation to FIG. 10, the connector 450 may include aninterface 500 having an inflection 502 that presents a deviation fromthe straight line interface and the parallel alignment of the femaleconnector interface 428 and the male connector interface 500 along theinsertion axis 476 as the connectors are mated. In one exemplaryembodiment, the types of inflections described herein with regard to thecurrent invention may be positioned from and end of the conductiveinsert to the start of the shoulder radius for the exemplary connectors.

In the exemplary embodiment of FIGS. 11 and 12, the inflection 502presents a discontinuity in the male connector interface 500, such thatthe interface 500 has two distinct portions 504 and 506. One portion 504extends prior to or before the inflection 502 as the connectors aremated, and the other portion 506 extends subsequent to or after theinflection 502 as the connectors are mated. The portion 504 before theinflection 502 may have, as shown in FIGS. 11 and 12, a steeper angle ofinclination relative to the insertion axis 476 than the portion 506.That is, the portion 504 may present a wider opening near the mouth 474of the connector 450, and may decrease in inner surface dimension atgreater rate than the portion 506 along the insertion axis.

The differing rate of change in inner surface diameter of the interface500 in the portions 504 and 506 allows, for example, the portion 504 topresent a wider opening to receive the female connector interfacewithout surface-to-surface engagement of the interface portion 504 andthe female connector interface 428. As such the resistance of theconnectors to being mated may be reduced because the surface-to-surfaceengagement of the connector interfaces occurs only along a portion oftheir interface lengths, as opposed to the entire length.

Moreover, the interface portion 506, which does fully engage the femaleconnector interface 428 with surface-to-surface engagement, may bedimensioned to provide a tighter interference fit with the femaleconnector interface 428 than for example the embodiment shown in FIG.10. Notably, however, because the interface portion 506 engages thefemale connector interface for only part of its length, the connectors400 and 450 may be mated with less operating force than if thestraight-line interface of FIG. 10 were utilized. When the inflection isused to generate additional contact pressure between the interfaceportion 506 and the female connector interface 428 in such a manner,voltage tracking along the interface 500 is believed to be less likelyin comparison to the straight line interface of FIG. 10. An increasedband of compression in the area of the inflection 502 has been found toprevent voltage tracking and associated failure conditions.

FIG. 22 provides exemplary test results comparing the failure rate forvoltage tracking conditions for the embodiment described in FIG. 10 ascompared to the embodiment described in FIGS. 11 and 12. The testresults for the embodiment of FIG. 10 are provided in the top twotables, while the test results for the embodiment described in FIGS. 11and 12 are provided in the bottom two tables. With regards to theembodiment of FIG. 10, two of the samples failed at 70 kV while 3 othersamples failed at 80 kV. However, with regards to the embodiment ofFIGS. 11 and 12, it can be seen from the bottom tables of FIG. 22 thatnone of the samples having the dual taper failed.

As shown in the test data of FIG. 22, the inflection 502 and itsincreased compression is also believed to improve dielectric performanceof the connector system. In one example, the connector system maycapably withstand voltages of 80 kV AC and impulses of 200 BIL (BasicImpulse Level). The improved dielectric performance of the connectorsystem based on the test results was unexpected.

FIGS. 13 and 14 illustrate another embodiment of a connector interfacewherein the male connector 450 is provided with a connector interface520 that is essentially the inverse of the interface 500 shown in FIGS.11 and 12, but providing similar benefits.

The interface 520 includes an inflection 522 that presents a deviationfrom the straight line interface and the parallel alignment of thefemale connector interface 428 and the male connector interface 520along the insertion axis 476 as the connectors are mated. The inflection522 presents a discontinuity in the male connector interface 520, suchthat the interface 520 has two distinct portions 524 and 526. Oneportion 524 extends prior to or before the inflection 522 as theconnectors are mated, and the other portion 526 extends subsequent to orafter the inflection 522 as the connectors are mated.

The portion 524 before the inflection 522 may have, as shown in FIGS. 13and 14, a lesser angle of inclination relative to the insertion axis 476than the portion 526. That is, the portion 524 may present a narroweropening, as opposed to the embodiment of FIGS. 11 and 12, near the mouth474 of the connector 450, and may decrease in inner surface dimension ata constant rate along the insertion axis. The interface portion 526after the inflection 522 however, increases in inner surface dimension.The different rate of change inner surface dimension of the interface520 before and after the inflection 522, one being negative the otherbeing positive, is advantageous for the reasons set forth below.

Moreover, the interface portion 524 prior to the inflection 522, may bedimensioned to provide a tighter interference fit with the femaleconnector interface 428 than for example the embodiment shown in FIG.10. When the inflection 522 is used to generate additional contactpressure between the interface portion 524 and the female connectorinterface 428 in such a manner, voltage tracking along the interface 520is believed to be less likely in comparison to the straight lineinterface of FIG. 10. An increased band of compression in the area ofthe inflection 502 is believed to prevent voltage tracking andassociated failure conditions, and is also believed to improvedielectric performance over the embodiment of FIG. 10 similar to theresults for the embodiment of FIGS. 11 and 12 presented in FIG. 22.

FIGS. 15 and 16 illustrate another embodiment of a connector interfacefor the connectors 400 and 450 wherein the male connector 450 isprovided with a connector interface 550 having a profile of a waveformwith smoothly rounded inflections 552 projecting inwardly toward theinsertion axis 476 and generating increased contact pressure between themale connector interface 550 and the female connector interface 428 inthe area of the inflections 552. In an alternative embodiment of theconnector interface of FIGS. 15 and 16, the inflections 552 may besquared off or provided with another geometry known to those of skill inthe art. Multiple inflections 552 may reduce voltage tracking moreeffectively than the embodiments shown in FIGS. 11-14. While FIGS. 15and 16 only show a couple of inflections 552, in one exemplaryembodiment, the connector interface 550 could include hundreds ofinflections; however those of ordinary skill in the art will recognizethat the number of inflections 552 could range from one to an infinitenumber of inflections 552 based on the side of the connector interfaceand the needs of the user.

Additionally, the waveform profile of the male connector interface 550results in contraction of the inner surface diameter of the interface550 on one side of the inflections 552 and expansion of the innersurface diameter of the interface on the other side of the inflections552. As such, the different rates of change in the inner surfacediameter before and after each inflection 552, one being positive andthe other being negative, provides for valleys 554 between theinflections 552. The valleys provide areas of reduced interference fitwherein that the interface 550 does not engage the surface of the femaleconnector interface 428 as tightly in the vicinity of the valleys 554.Therefore, like the embodiments of FIGS. 11-14, the embodiment of FIGS.15-16 provides for high pressure surface-to-surface engagement of thefemale connector interface 428 and the male connector interface 550 onlyalong a portion of the interface lengths. The partial pressuresurface-to-surface engagement may beneficially reduce an operating forcerequired to mate the connectors 400 and 450. Voltage tracking may alsobe beneficially reduced, and dielectric performance of the connectorsystem may be increased.

In addition, the waveform profile of the male connector interfaceprovides areas, or pockets, where the grease used to mate and separatethe connectors 400 and 450 can become trapped. Because the grease is notbeing forced along the interface, the grease has a more difficult timemigrating off the interface. Furthermore, the trapping of the grease inthe pockets helps to keep the grease on the interfaces, making theconnectors 400 and 450 easier to separate.

FIGS. 17 and 18 illustrate still another embodiment of a connectorinterface for the connectors 400 and 450 wherein the male connector 450is provided with a connector interface 570 having an inflection 572 anda generally linear portion 570 before the inflection 572 and acurvilinear portion 576 after the inflection 572. The portion 574 mayprovide surface-to-surface engagement with the connector interface 428with greater or equal contact pressure than the embodiment of FIG. 10,for example. The curvilinear portion 576 may be concave and provide anarea of less interference between the female connector interface 400such that reduced hoop stress occurs between the interface portion 576and the female connector interface 428.

The different rate of change of inner surface dimension in the interface470 before and after the inflection 572, provides for similar benefitsto the above-described embodiments. Tight surface-to-surface engagementof the female connector interface 428 and the male connector interface570 only along a portion of the interface lengths beneficially reducesan operating force required to mate the connectors 400 and 450, while anincreased compression force in the interface portion 504 effectivelyprevents voltage tracking and offers improved dielectric performance.

In addition, the curvilinear portion of the male connector interfaceprovides an area, or pocket, where the grease used to mate and separatethe connectors 400 and 450 can become trapped. Because the grease is notbeing forced along the interface, the grease has a more difficult timemigrating off the interface. Furthermore, the trapping of the grease inthe pocket helps to keep the grease on the interface, making theconnectors 400 and 450 easier to separate.

In addition, the larger volume of air trapped on the interface duringconnector insertion is more likely to “burp” the air out of theinterface leading to improved dielectric performance.

FIG. 19 illustrates another embodiment of a connector interface for theconnectors 400 and 450, wherein the male connector 450 is provided witha connector interface 580 having multiple inflections 582 thatcriss-cross one another at or substantially near right angles,generating a waffle pattern. Each inflection 582 may providesurface-to-surface engagement with the connector interface 428 with thesame or greater contact pressure than the embodiment of FIG. 10. Theareas 584 between the inflections 582 may be recessed from the level ofthe inflection so as to put less contact pressure on the connectorinterface. The recessed areas 584 may be flat, concave, convex, oranother geometry known to those of skill in the art.

The multiple changes in surface dimension in the interface 580 at andaround the inflections 582 may provide similar benefits to theembodiments described in FIGS. 11-15. Reduced compression engagement ofthe female connector interface 428 along a portion of the interfacesurface area beneficially reduces the operating force required to mateand separate the connectors 400 and 450, while the increased compressionforce at the inflections 582 effectively prevents or reduces voltagetracking and offers improved dielectric performance. Those of ordinaryskill in the art will recognize that modifications to the geometricdesign of the connector interface 580, such as the “diamond shape” ofFIG. 20 may be made while accomplishing the same benefits as the waffledesign, including, but not limited to, circular, triangular,rectangular, hexagonal, octagonal and other shaped versions of theinflections 582 shown in FIGS. 19 and 20.

In addition, the recessed areas 584 of the male connector interface 580provide an area, or pocket, where the grease used to mate and separatethe connectors 400 and 450 can become trapped. Because the grease is notbeing forced along the interface, the grease has a more difficult timemigrating off the interface. Furthermore, trapping of the grease in thepocket 584 helps to keep the grease on the interface, making theconnectors 400 and 450 easier to separate.

FIG. 21 illustrates a side view of still another embodiment of aconnector interface for the connectors 400 and 450, wherein the maleconnector 450 is provided with a connector interface 590 having multiplespherical dimples 591, each dimple 591 having a circular inflection 592and a recessed portion 596 inside of the inflection 592. The circularinflection 592 may provide surface-to-surface engagement with theconnector interface 428 with greater or equal contact pressure than theembodiment of FIG. 10. The recessed portion 596 may be concave andprovide an area of less interference fit between the female connectorinterface 400 such that surface-to-surface pressure is less between therecessed portion 596 and the female connector interface 428 than betweenthe female connector interface 428 and the circular inflection 592.

The multiple changes in surface dimension in the interface at and aroundthe inflections 592 and the recessed portion 596 may provide similarbenefits to the embodiments described in FIGS. 11-15. The reduction inthe surface-to-surface pressure of the female connector interface 428along a portion of the interface 590 surface area beneficially reducesthe operating force required to mate and separate the connectors 400 and450, while the increased compression force at the inflections 592effectively prevents or reduces voltage tracking and offers improveddielectric performance.

In addition, the recessed portion 596, or dimple, of the male connectorinterface 590 provides an area, or pocket, where the grease used to mateand separate the connectors 400 and 450 can become trapped. Because thegrease is not being forced along the interface, the grease has a moredifficult time migrating off the interface. Furthermore, trapping of thegrease in the dimple 596 helps to keep the grease on the interface 590,making the connectors 400 and 450 easier to separate.

Having now described various embodiments of connector interfaces havingone or more inflections creating bands of increased compression aroundthe full circumference of the mated connector interfaces, it isrecognized that further embodiments may be derived with straightforwardmodification of, and possibly combining aspects of, the embodimentsillustrated in FIGS. 11-14. For example, the multiple inflections ofFIG. 13 may be incorporated into the embodiments of FIGS. 10, 11 and 14by introducing additional portions in the connector interfaces. Asanother example, the interface of FIG. 13 could be emulatedgeometrically with a saw tooth design without rounded inflections andvalleys as illustrated. The illustrated embodiments are but a fewexamples of potential embodiments of connector interfaces.

While all the foregoing embodiments shown in FIGS. 11-15 includemodified connector interfaces in the male connector 450 without changingthe connector interface 428 of the female connector 400, it isunderstood that inflections may likewise be provided in the femaleconnector interface 428 in lieu of the connector interface of the maleconnector 450 to provide similar effects and advantages if desired. Instill further embodiments, inflections may be provided in both the maleconnector 450 and the female connector 400 in order to more completelyoptimize operating forces required to mate the connectors, meet specificperformance requirements, or to achieve still higher connector ratings.The inventive connector interfaces may facilitate size reduction of theinterfaces while achieving a desired current rating, or alternativelymay be utilized to increase the voltage rating of the connector, whilemaintaining a given size of the interfaces. The connector interfaces maybe implemented at relatively low cost using known manufacturingtechniques.

Finally, while the interfaces shown in FIGS. 11-14 are described inrelation to the energized break female connector 400 described in detailherein, the disclosed interfaces and their benefits may accrue equallyto loadbreak and deadbreak separable connector systems as well. Theinventive connector interfaces are not intended to be limited only toenergized break connector systems.

In one exemplary embodiment, a separable insulated connector for a powerdistribution system has been described that includes an elastomericinsulating housing having an open end and a connector interfaceextending inward from the open end, the connector interface having aninner surface defining a passage dimensioned to slidably receive amating connector along an axial insertion axis; wherein acircumferential dimension of the passage axis varies along the insertionaxis; wherein the connector interface comprises at least one inflectionextending circumferentially on the inner surface; and wherein a rate ofchange of the circumferential dimension is different before and afterthe inflection. In an exemplary embodiment, the rate of change of thecircumferential dimension is greater before the inflection point thanafter the inflection point. In another exemplary embodiment, the rate ofchange of the circumferential dimension is constant before theinflection. In another exemplary embodiment, the inflection pointgenerates an increased band of contact pressure with the matingconnector. In another exemplary embodiment, the inner surface of theconnector interface includes multiple inflection points. In anotherexemplary embodiment, the inner surface of the connector interfacebefore the inflection point provides a clearance for the matingconnector, and the inner surface after the inflection point engages themating connector. In another exemplary embodiment, the inflection marksa discontinuity in the inner surface. In another exemplary embodiment,the rate of change of the circumferential dimension is negative beforethe inflection and positive after the inflection. In another exemplaryembodiment, the inner surface after the inflection is concave. Inanother exemplary embodiment, the connector also includes an insertdefining a faraday cage, the inner surface extending from an end of thefaraday cage to the open end of the housing. In another exemplaryembodiment, the mating connector has an elastomeric housing defining agenerally conical interface, the passage dimensioned to securely retainthe conical interface.

In one exemplary embodiment, a separable insulated connector for makingor breaking an energized connection in a power distribution networkincludes a contact probe, a conductive insert defining a faraday cagearound a portion of the probe, an elastomeric insulation housingsurrounding the contact probe and the conductive insert, the housingdefining an open ended connector interface, the connector interfaceextending about the probe forward of the conductive insert and having atapered circumferential dimension along an axis of the probe; whereinthe connector interface receives a mating connector; and wherein theconnector interface comprises at least one inflection extendingcircumferentially on an inner surface thereof, the inflection alteringan amount of insertion force necessary to engage the mating connector.In one exemplary embodiment, the circumferential dimension varies alongthe axis at a different rate before and after the inflection. In anotherexemplary embodiment, the rate of change of the circumferentialdimension is greater before the inflection than after the inflection. Inanother exemplary embodiment, the rate of change of the circumferentialdimension is constant before the inflection. In another exemplaryembodiment, the inflection point increases contact pressure relative toanother portion of the inner surface. In another exemplary embodiment,the inner surface of the connector interface includes multipleinflection points. In another exemplary embodiment, the clearance forthe mating connector is provided on one side of the inflection, and theinner surface engages the mating connector at the inflection. In anotherexemplary embodiment, the inflection marks a discontinuity in the innersurface. In another exemplary embodiment, the rate of change of thecircumferential dimension is negative before the inflection and positiveafter the inflection. In another exemplary embodiment, the inner surfaceafter the inflection is concave. In another exemplary embodiment, themating connector has an elastomeric housing defining a generally conicalinterface, the passage dimensioned to securely retain the conicalinterface. In another exemplary embodiment, the connector also includesa ground plane provided on an outer surface of the housing.

In one exemplary embodiment, a separable insulated connector system tomake or break a connection in a power distribution system has beendescribed that includes a first connector comprising a first elastomerichousing defining a first connector interface on an outer surfacethereof; and a second connector comprising a second elastomeric housingdefining a second connector interface on an inner surface thereof;wherein each of the first and second connector interfaces are tapered;and wherein the connector interfaces are not parallel to one anotherprior to connector engagement, but are parallel when the connectors areengaged. In another exemplary embodiment, the connector interfacesengage one another only partially along a length of the interfaces. Inanother exemplary embodiment, the first connector comprises aninsulation system configured to make or break energized connections atrated voltage without instances of flashover. In another exemplaryembodiment, the first connector interface is generally conical. Inanother exemplary embodiment, one of the first and second connectorinterfaces comprises at least one inflection extending circumferentiallyon the respective interface, wherein a circumferential dimension of theinterface varies along the axis at a different rate before and after theinflection. In another exemplary embodiment, the rate of change of thecircumferential dimension is greater before the inflection than afterthe inflection. In another exemplary embodiment, the rate of change ofthe circumferential dimension is constant before the inflection. Inanother exemplary embodiment, the inner surface includes multipleinflection points. In another exemplary embodiment, the inner surfacebefore the inflection point provides a clearance for the matingconnector, and the inner surface after the inflection point provides aninterference fit with the mating connector. In another exemplaryembodiment, the inflection marks a discontinuity in the inner surface.In another exemplary embodiment, the rate of change of thecircumferential dimension is negative before the inflection and positiveafter the inflection. In another exemplary embodiment, the inner surfaceafter the inflection is concave. In another exemplary embodiment, eachof the first and second connectors further comprise a ground planeprovided on an outer surface of the respective housings. In anotherexemplary embodiment, the inflection is provided on the second connectorinterface.

In one exemplary embodiment, a separable insulated connector device fora power distribution system has been described that includes anelastomeric housing comprising an interior, an exterior, and an open endthe interior of the housing comprising a connector interface, whereinthe connector interface extends inward from the open end along theinterior, the connector interface comprising; an inner surface defininga passage dimensioned to slidably receive a mating connector along aninsertion axis; an inflection extending circumferentially on the innersurface and comprising an increased band of contact pressure with themating connector; wherein the rate of change of the circumferentialdimension of the inner surface is greater along a first portion of theinner surface between the open end and the inflection than along asecond portion of the inner surface between the inflection and an endopposite the open end and the circumferential dimension of the innersurface is greater along the first portion of the inner surface thanalong the second portion of the inner surface; a probe assembly affixedto the interior of the elastomeric housing, the probe assemblycomprising a contact probe having a first end and a second end, thefirst end of the contact probe coupled to the contact assembly andextending along a passage in the connector interface; a semi-conductiveinsert coupled to the contact assembly, the semi-conductive insertcomprising a faraday cage the faraday cage comprising a first and asecond end, wherein the inner surface extends from the first end of thefaraday cage to the open end of the elastomeric insulating housing; anda ground plane positioned along the exterior of the elastomeric housing.

In one exemplary embodiment, a separable insulated connector device fora power distribution system has been described that includes anelastomeric housing comprising an interior, an exterior, and an openend, the interior of the housing comprising a connector interface,wherein the connector interface extends inward from the open end alongthe interior, the connector interface comprising; an inner surfacedefining a passage dimensioned to slidably receive a mating connectoralong an insertion axis; a plurality of inflections, each inflectioncomprising a dimple wherein a first portion of the dimple extendsoutward from the inner surface into the passage and a second portion ofthe dimple extending into the inner surface, the first portion of thedimple comprising an increased band of contact pressure with the matingconnector and the second portion of the dimple comprising a pocket forreceiving a lubricant; a probe assembly affixed to the interior of theelastomeric housing, the probe assembly comprising a contact probehaving a first end and a second end, the first end of the contact probecoupled to the contact assembly and extending along a passage in theconnector interface; a semi-conductive insert coupled to the contactassembly, the semi-conductive insert comprising a faraday cage thefaraday cage comprising a first and a second end, wherein the innersurface extends from the first end of the faraday cage to the open endof the elastomeric insulating housing; and a ground plane positionedalong the exterior of the elastomeric housing.

In one exemplary embodiment, a separable insulated connector device fora power distribution system has been described that includes anelastomeric housing comprising an interior, an exterior, and an openend, the interior of the housing comprising a connector interface,wherein the connector interface extends inward from the open end alongthe interior, the connector interface comprising; an inner surfacedefining a passage dimensioned to slidably receive a mating connectoralong an insertion axis; a plurality of inflections, each inflectioncomprising a geometric pattern wherein a first portion of the geometricpattern extends outward from the inner surface into the passage and asecond portion of the geometric pattern extending into the innersurface, the first portion of the geometric pattern comprising anincreased band of contact pressure with the mating connector and thesecond portion of the geometric patter comprising a pocket for receivinga lubricant; a probe assembly affixed to the interior of the elastomerichousing, the probe assembly comprising a contact probe having a firstend and a second end, the first end of the contact probe coupled to thecontact assembly and extending along a passage in the connectorinterface; a semi-conductive insert coupled to the contact assembly, thesemi-conductive insert comprising a faraday cage the faraday cagecomprising a first and a second end, wherein the inner surface extendsfrom the first end of the faraday cage to the open end of theelastomeric insulating housing; and a ground plane positioned along theexterior of the elastomeric housing. In another exemplary embodiment,the geometric pattern is a quadrilateral. In another exemplaryembodiment, the plurality of inflections comprises a waffle pattern.

In one exemplary embodiment, a separable insulated connector device fora power distribution system has been described that includes anelastomeric housing comprising an interior, an exterior, and an open endthe interior of the housing comprising a connector interface, whereinthe connector interface extends inward from the open end along theinterior, the connector interface comprising: an inner surface defininga passage dimensioned to slidably receive a mating connector along aninsertion axis; a plurality of inflections extending circumferentiallyon the inner surface, each inflection comprising an increased band ofcontact pressure with the mating connector; a plurality of troughs, thetroughs positioned adjacent to and along a side of each inflection, eachtrough comprising a pocket of decreased contact pressure with the matingconnector and capable of receiving a lubricant therein; wherein thecircumferential dimension of the inner surface at the peak of eachtrough is less as each trough is positioned farther away from the openend; a probe assembly affixed to the interior of the elastomerichousing, the probe assembly comprising a contact probe having a firstend and a second end, the first end of the contact probe coupled to thecontact assembly and extending along a passage in the connectorinterface; a semi-conductive insert coupled to the contact assembly, thesemi-conductive insert comprising a faraday cage the faraday cagecomprising a first and a second end, wherein the inner surface extendsfrom the first end of the faraday cage to the open end of theelastomeric insulating housing; and a ground plane positioned along theexterior of the elastomeric housing.

In one exemplary embodiment, a separable insulated connector device formaking or breaking an energized connection in a power distributionnetwork has been described that includes a contact means for extendingalong a passage in a connector interface and providing a contact pointbetween the connector and a mating connector; a means for preventing acorona discharge in the along an interface between the connector and themating connector when the connector and the mating connector are mated,the means comprising a conductive insert positioned around a portion ofthe contact means; a means for providing insulation around the contactmeans and the corona discharge prevention means, the insulation meansdefining an open ended interface having an inner surface, the interfaceextending about the contact means forward of the corona dischargeprevention means and having a tapered circumferential dimension along anaxis of the contact means; wherein the interface receives a means forslidable insertion into the interface; and wherein the inner surfacecomprises at least one pressure means comprising an inflection, whereinthe pressure means extends into the interface from the insulation meansand provides an increased amount of contact pressure on the means forslidable insertion into the interface. In another exemplary embodiment,the inner surface comprises a plurality of pressure means; each pressuremeans having a geometric shape. In another exemplary embodiment, theinner surface between the pressure means and one end of the insulationmeans comprises a means for retaining a lubricant between the insertionmeans and the inner surface. In another exemplary embodiment, thepressure means further comprises a means for retaining a lubricantbetween the insertion means and the inner surface.

In one exemplary embodiment, a switchgear has been described thatincludes a protective enclosure comprising a first end and a second end;a plurality of cables coupled to the lower end of the enclosure eachcable coupled to a connector component wherein the connector componentcomprises and insulating connector and a mating connector and whereinthe insulating connector comprises: a contact probe; a conductive insertdefining a faraday cage around a portion of the probe; an elastomericinsulation housing surrounding the contact probe and the conductiveinsert, the housing defining an open ended connector interface, theconnector interface extending about the probe forward of the conductiveinsert and having a tapered circumferential dimension along an axis ofthe probe; wherein the connector interface receives the matingconnector; and wherein the connector interface comprises at least oneinflection extending out from the inner surface into the connectorinterface, the inflection altering an amount of insertion forcenecessary to engage the mating connector; a plurality of switchingcomponents; each switching component coupled to one of the cablesthrough the connector component; and an internal bus bar coupled to theswitching components.

In one exemplary embodiment, a method has been described that includesthe steps of providing an insulating housing, the housing configured tocomprise an open end and a connector interface; positioning a contactassembly to an interior of the housing; coupling a contact probe to thecontact assembly inside the housing, the contact probe configured tohave a first end and a second end, the first end affixed to the contactassembly and the probe extending along a passage in the connectorinterface; associating a conductive extension member with the second endof the contact probe, the conductive extension member positioned toextend away from the connector interface; and providing at least oneinflection along a surface of the connector interface, the inflectionpoint generating an increased area of contact pressure with a matingconnector. In another exemplary embodiment, the inflection extendscircumferentially along the surface of the connector interface. Inanother exemplary embodiment, the method also includes providing theconnector interface with a first rate of circumferential change betweenthe open end and the inflection and providing the connector interfacewith a second rate of circumferential change between the inflection andthe contact assembly. In another exemplary embodiment, the first rate ofcircumferential change is greater than the second rate ofcircumferential change. In another exemplary embodiment, the first rateof circumferential change is negative and the second rate ofcircumferential change is positive. In another exemplary embodiment, themethod includes the steps of providing a plurality of inflections alongthe connector interface, each inflection having a geometric shape, acircumference of the geometric shape generating an increased area ofcontact pressure with the mating connector and providing a plurality oflower contact pressure areas along the connector interface, wherein eachnon-contact area is adjacent to at least one of the inflections. Inanother exemplary embodiment, each non-contact area is capable ofreceiving and storing a lubricant in the non-contact area when themating connector is mated with the connector. In another exemplaryembodiment, the geometric shape is a dimple. In another exemplaryembodiment, the geometric shape is a parallelogram.

In one exemplary embodiment, a system for power distribution has beendescribed that includes a power generating means for generatingelectricity; a power transmission means electrically coupled on a firstend to the power generating means; a first electrical isolation meanselectrically coupled to a second end of the power transmission means; anelectrical transforming means electrically coupled to the firstelectrical isolation means and a second electrical isolation means,wherein each electrical isolation means comprises: an elastomericinsulating means having an open end and means for interfacing a matingconnector, the interfacing means extending inward from the open end andhaving an inner surface defining a passage dimensioned to slidablyreceive the mating connector along an axial insertion axis; wherein thecircumferential dimension of the passage axis varies along the insertionaxis; wherein the interfacing means further comprises at least one meansfor providing increased pressure along the mating connector, wherein therate of change of the circumferential dimension is different before andafter the increased pressure means; and at least one means for consumingthe electricity. In another exemplary embodiment, the increased pressuremeans provides a band of contact pressure with the mating connector. Inanother exemplary embodiment, the increased pressure means comprises aplurality of increased pressure means, each comprising a geometricshape, wherein at least the circumference of the geometric shapeprovides increased pressure against the mating connector. In anotherexemplary embodiment, the geometric shape is a dimple. In anotherexemplary embodiment, the geometric shape is a parallelogram. In anotherexemplary embodiment, the change of circumferential dimension of thepassage axis is greater between the open end and the increased pressuremeans than the change of circumferential dimension of the passage axisbetween the increased pressure means and an end opposite the open end.

In one exemplary embodiment, a system for power distribution has beendescribed that includes a power generating plant for generatingelectrical power; at least one electrical transmission cableelectrically coupled on a first end to the power generating plant; ahigh voltage switchgear electrically coupled to a second end of theelectrical transmission cable; an electrical transformer electricallycoupled to the high voltage switchgear and a lower voltage switchgear,wherein each switchgear comprises: a connector to the switchgear theconnector comprising: an elastomeric insulating housing having an openend and a connector interface extending inward from the open end, theconnector interface having an inner surface defining a passagedimensioned to slidably receive a mating connector along an axialinsertion axis; wherein a circumferential dimension of the passage axisvaries along the insertion axis; wherein the connector interfacecomprises at least one inflection extending circumferentially on theinner surface; and wherein a rate of change of the circumferentialdimension is different before and after the inflection; and at least oneconsumer that consumes the generated electrical power. In anotherexemplary embodiment, the rate of change of the circumferentialdimension is greater before the inflection point than after theinflection point. In another exemplary embodiment, the rate of change ofthe circumferential dimension is constant before the inflection. Inanother exemplary embodiment, the inflection point generates anincreased band of contact pressure with the mating connector. In anotherexemplary embodiment, the inner surface includes multiple inflectionpoints. In another exemplary embodiment, the inner surface before theinflection point provides a clearance for the mating connector, and theinner surface after the inflection point engages the mating connector.In another exemplary embodiment, the inflection marks a discontinuity inthe inner surface. In another exemplary embodiment, the rate of changeof the circumferential dimension is negative before the inflection andpositive after the inflection. In another exemplary embodiment, theinner surface after the inflection is concave. In another exemplaryembodiment, the connector interface includes a plurality of inflections,each inflection comprising a geometric shape, wherein at least thecircumference of the geometric shape provides increased pressure againstthe mating connector. In another exemplary embodiment, the geometricshape is a dimple. In another exemplary embodiment, the geometric shapeis a parallelogram. The interior of the geometric shape comprises arecessed area, wherein the recessed area is capable of receiving andstoring a lubricant when a mating connector applies a force against theconnector interface.

While the novel aspects have been described in terms of various specificembodiments, those skilled in the art will recognize that these aspectscan be practiced with modification within the spirit and scope of theclaims.

1. A separable insulated connector for a power distribution system, theconnector comprising: an electrical contact; a conductive insertdefining a faraday cage around a portion of the electrical contact; anelastomeric insulating housing having an open end and a connectorinterface extending inward from the open end, the connector interfacehaving an inner surface defining a passage dimensioned to slidablyreceive a mating connector along an axial insertion axis; wherein theconnector interface comprises a mouth; wherein a circumferentialdimension of the passage varies along the insertion axis; wherein aregion of the connector interface overlaps the faraday cage; wherein theconnector interface comprises at least one inflection extendingcircumferentially on the inner surface, the at least one inflectionbeing located between the mouth and the region of the connectorinterface that overlaps the faraday cage; and wherein a rate of changeof the circumferential dimension is different before and after theinflection.
 2. The connector of claim 1, wherein the rate of change ofthe circumferential dimension is greater before the inflection pointthan after the inflection point.
 3. The connector of claim 1, whereinthe rate of change of the circumferential dimension is constant beforethe inflection.
 4. The connector of claim 1, wherein the inflectionpoint generates an increased band of contact pressure with the matingconnector.
 5. The connector of claim 1, wherein the inflection marks adiscontinuity in the inner surface.
 6. The connector of claim 1, whereinthe rate of change of the circumferential dimension is negative beforethe inflection and positive after the inflection.
 7. A separableinsulated connector for making or breaking an energized connection in apower distribution network, the connector comprising: an electricalcontact; a conductive insert defining a faraday cage around a portion ofthe electrical contact; an elastomeric insulation housing surroundingthe electrical contact and the conductive insert, the housing definingan open ended connector interface comprising a mouth, the connectorinterface extending about the electrical contact forward of theconductive insert and having a tapered circumferential dimension alongan axis of the electrical contact; wherein the connector interfacereceives a mating connector; wherein a region of the connector interfaceoverlaps the faraday cage; and wherein the connector interface comprisesat least one inflection extending circumferentially on an inner surfacethereof between the mouth and the region of the connector interface thatoverlaps the faraday cage, the inflection altering an amount ofinsertion force necessary to engage the mating connector.
 8. Theconnector of claim 7, wherein a rate of change of the circumferentialdimension is different before and after the inflection.
 9. The connectorof claim 8, wherein the rate of change of the circumferential dimensionis constant before the inflection.
 10. The connector of claim 8, whereinthe rate of change of the circumferential dimension is greater beforethe inflection than after the inflection.
 11. A separable insulatedconnector for a power distribution system, the connector comprising: anelastomeric housing comprising an interior, an exterior, a mouth, and anopen end the interior of the housing comprising a connector interface,wherein the connector interface extends inward from the open end alongthe interior, the connector interface comprising: a mouth; an innersurface defining a passage dimensioned to slidably receive a matingconnector along an insertion axis; an inflection extendingcircumferentially on the inner surface and comprising an increased bandof contact pressure with the mating connector; wherein the rate ofchange of the circumferential dimension of the inner surface is greateralong a first portion of the inner surface between the open end and theinflection than along a second portion of the inner surface between theinflection and an end opposite the open end and the circumferentialdimension of the inner surface is greater along the first portion of theinner surface than along the second portion of the inner surface; aprobe assembly affixed to the interior of the elastomeric housing, theprobe assembly comprising a contact probe having a first end and asecond end, the first end of the contact probe coupled to the contactassembly and extending along a passage in the connector interface; asemi-conductive insert coupled to the probe assembly, thesemi-conductive insert comprising a faraday cage being overlapped by aregion of the connector interface, the faraday cage comprising a firstand a second end, wherein the inner surface extends from the first endof the faraday cage to the open end of the elastomeric insulatinghousing; and a ground plane positioned along the exterior of theelastomeric housing, wherein the inflection is located between the mouthand the region of the connector interface that overlaps the faradaycage.
 12. The connector of claim 11, wherein the rate of change of thecircumferential dimension is constant before the inflection.
 13. Aseparable insulated connector for making or breaking an energizedconnection in a power distribution network, the connector comprising: acontact means for extending along a passage in a connector interface andproviding a contact point between the connector and a mating connector;a means for preventing a corona discharge along an interface between theconnector and the mating connector when the connector and the matingconnector are mated, the means comprising a conductive insert positionedaround a portion of the contact means; a means for providing insulationaround the contact means and the corona discharge prevention means, theinsulation means defining an open ended interface having a mouth and aninner surface, the interface extending about the contact means forwardof the corona discharge prevention means and having a taperedcircumferential dimension along an axis of the contact means; wherein aregion of the interface overlaps the means for preventing coronadischarge; wherein the interface receives a means for slidable insertioninto the interface; and wherein the inner surface comprises at least onepressure means comprising an inflection located between the mouth andthe region of the interface that overlaps the means for preventingcorona discharge, and wherein the pressure means extends into theinterface from the insulation means and provides an increased amount ofcontact pressure on the means for slidable insertion into the interface.14. The connector of claim 13, wherein a rate of change of thecircumferential dimension is different before and after the inflection.15. The connector of claim 14, wherein the rate of change of thecircumferential dimension is constant before the inflection.
 16. Theconnector of claim 14, wherein the rate of change of the circumferentialdimension is greater before the inflection than after the inflection.17. A method comprising: providing an insulating housing, the housingconfigured to comprise an open end and a connector interface having amouth; positioning a contact assembly to an interior of the housing;coupling a contact probe to the contact assembly inside the housing, thecontact probe configured to have a first end and a second end, the firstend affixed to the contact assembly and the probe extending along apassage in the connector interface; providing a conductive insertdefining a faraday cage around a portion of the contact probe such thatthe faraday cage is overlapped by a region of the contacts a region ofthe insulating housing; associating a conductive extension member withthe second end of the contact probe, the conductive extension memberpositioned to extend away from the connector interface; and providing atleast one inflection along a surface of the connector interface, theinflection pint generating an increased area of contact pressure with amating connector, wherein the at least one inflection is provided at alocation between the mouth and the region of the connector interfacethat contacts the faraday cage.
 18. The method of claim 17, wherein thesurface of the connector interface comprises a tapered circumferentialdimension.
 19. The method of claim 18, wherein a rate of change of thecircumferential dimension is different before and after the inflection.20. The method of claim 19, wherein the rate of change of thecircumferential dimension is greater before the inflection than afterthe inflection.